For the best part of a year Alexis Sanchez and Mesut Ozil have appeared incapable of flexing anything with quite the same sort of purpose with which they flexed the threat of the Bosman free transfer. Since they clambered victorious to the top of the charts for the Premier League's best-paid players, in fact, they have vanished almost entirely from the highlights reels and the goal rankings. Unai Emery has virtually given up on Ozil who was unable to turn the tie with a late cameo appearance on Friday night and is available on loan with Arsenal prepared to subsidise his enormous wages if anyone is interested. Alexis Sanchez scored against his old club as Manchester United beat Arsenal on Friday night Sanchez, too, has proved to be variously anonymous, absent, unsettled and unfit since his move to Manchester United. There was, however, a certain sense of inevitability among the natives at the Emirates Stadium that this would be the night when he became relevant once again. Sure enough, little more than half an hour had ticked by when Sanchez seized on a pass by Romelu Lukaku, danced around Petr Cech and scored for the first time since early October. A year has passed since his Manchester United debut at this same stage of the FA Cup, a comfortable win at Yeovil, after which Jose Mourinho hailed the Chilean for his 'maturity and class'. Mourinho was still basking in the audacity of the transfer coup. United had beaten Manchester City to his signature and Sanchez pocketed a £6.75million signing-on fee and an annual salary of £20.35m plus bonuses at Old Trafford. Chilean Sanchez dinked the ball over goalkeeper Petr Cech to open the scoring in the Cup tie He was handed fabled No 7 shirt and made the awkward star of a cheesy unveiling video, tinkling at the ivories of an upright piano. It was that sort of a transfer window, but none of this went down well at Arsenal, where they once hung a banner in honour of Sanchez and his pet dogs Atom and Humber. They longed to keep a player who scored 80 goals in 166 games over three-and-a-half years and distracted from deeper problems, and someone thought the dog banner might appeal to his sense of loyalty, which was almost as laughable as the piano stunt. So they jeered his name when the teams were announced on Friday night and they booed his early touches as he struggled to get into the game, playing on United's left flank where he was up against Ainsley Maitland-Niles, inexperienced and out of position. Sanchez was muted in his celebrations but team-mate Jesse Lingard was much more vocal They cheered when Maitland-Niles cut out his crosses and miscued an attempted clearance but they but fell silent when he beat Cech and finished coolly from a tight angle. It was his first Manchester United goal away from Old Trafford. Sanchez celebrated, pointed with both hands to the sky and the visitors were off and running, never pegged back. Home fans hurled more abuse and then booed most loudly when his number went up and he was replaced by Anthony Martial with 19 minutes to go and yet none of it came close to the European yardstick of a truly hostile return: Luis Figo and the pig's head at the Nou Camp. Ole Gunner Solskjaer ruffled his hair as he took his seat on the bench. Perhaps Solskjaer can coax something from him as he has with others since his arrival; maybe recharge his desire. Manager Ole Gunner Solskjaer ruffled Sanchez's hair after substituting him off on 72 minutes There is not the same trademark intensity of his heyday at Arsenal. Sanchez was never a sophisticated technician like Ozil but he was always dynamic and industrious, often capable of influencing games by force of will. His performance was far short of his best and United are more dangerous with the direct pace of Martial and Marcus Rashford up front but the goal can only help Sanchez restore his confidence. His return to fitness might help him find his rhythm and another FA Cup tie will offer another chance to play. Potential match action for Ozil, meanwhile, is hard to identify. He could not force his way into Arsenal's weakened FA Cup team and has scored only five goals since signing his new contract, thought to be worth £350,000 a week, almost a year ago. Mesut Ozil came off the bench for the final half an hour but was unable to produce any magic He has not started a game since Boxing Day when he was replaced at half-time, and he was on the bench against United. Ozil may have global commercial appeal but his numbers do not stand scrutiny at the Emirates, where money is tight and Emery bemoans the fact he only has the funds to make loan signings this month. Still, the Arsenal supporters roared their German playmaker onto the pitch as a second-half substitute. They were trailing and in need of inspiration and they know he has the ability to conjure chances. That has never been in question. Ozil came on and threaded a few passes and delivered some teasing set-pieces but Martial settled the outcome with the third and this night of the heroes who held Arsenal hostage belonged to Sanchez. All rights reserved for this news site dailymail and under his responsibility